#define _CRT_SECURE_NO_WARNINGS 1
#include <stdio.h>
#include <math.h>
int main()
{
	double input = 0;
	while (1)
	{
		scanf("%lf", &input);
		if (input < 0 || input > 1000)
		{
			printf("please input again:");
				continue;
		}
		else
		{
			int m = (int)input;
			int n = sqrt(m);
			printf("\nanswer=%d", n);
			break;
		}
	}
	return 0;
}